The present invention provides a charging system and charging method. An online charging system and an offline charging system are interconnected via a shared data center to make up a dual-engine structure, which is able to implement online charging, offline charging, account sharing, switching between prepaid and postpaid modes, and binding of voice and data services. With the invention, an operator can possess more flexible charging and control capabilities, lower the cost of arrearage, and have stronger competitiveness.